Process for determining the position and coplanarity of the leads of components

ABSTRACT

In order to determine the position and/or to check the separation of the leads (A) of components (B), a direct shadow of the region of the leads at one side of the component is generated on the photosensitive surface of a local resolution optoelectronic transducer (W4). If in each case one shadow is generated successively from two different directions, the coplanarity of the leads (A) may also be checked. Preferably, the local resolution optoelectronic transducer (W4) and the light sources for casting the shadow are directly secured to the equipping head (BK4). By integrating the determination system into the equipping head, the lead position can be determined and the separation and coplanarity of the leads can be checked without delay.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to a method and apparatus forchecking the position of leads on an electrical component.

2. Description of the Related Art

In the automatic equipping of printed circuit boards or ceramicsubstrates with SMD components, the individual components are removedfrom a magazine or a feeding device by means of a equipping head and arethen positioned in a predetermined position on the printed circuit boardor the ceramic substrate. Since the components exhibit, in the magazineor in the collection position of a feeding device, a position toleranceof approximately 1 mm, but must be positioned on the printed circuitboard or the ceramic substrate with high accuracy, an automaticdetermination of position and correction are necessary. Furthermore,especially in the case of SMD components with a large number of pins,the separation and the coplanarity of the leads must be checked. Thedetermination of position and the checking of separation and coplanarityshould in this case take as little time as possible, in order to permita high degree of equipping performance of the automatic equippingsystem. Increasing component dimensions of up to 70×70 mm, decreasingseparation of the leads of down to 0.3 mm and stringent requirementsplaced upon the speed of equipping create considerable difficulties inachieving the mentioned objects.

Known arrangements for determining the position and checking theseparation of the leads of components obtain the image of the componentor sections of the component, by means of an objective lens, onto aplanar CCD camera and ascertain, using digital image processing, theposition of the component leads and the separation of the leads. Withsuch arrangements, a coplanarity check is not possible.

In other known arrangements for determining the position and checkingthe separation of the leads of components, the components are placedonto an optically transparent plate, on which a shadow of theilluminated leads is generated. The shadow edges of the leads are thenimaged from below by means of an objective lens onto a planar CCDcamera, so that in this case also, again, the position of the componentleads and the separation of the leads can be ascertained using digitalimage processing. A coplanarity check is made possible using thesearrangements in that the leads are successively illuminated from twodifferent directions (cf. European Patent Application 0 425 722 and PCTPublished Application 91/15104).

As a result of the increasing component size, as well as the morestringent requirements imposed on accuracy and the required shortdetermination times, significant limits are placed on a use of the knownarrangements for determining the position, checking the separation andpossibly checking the coplanarity of the leads of components, since:

In the case of a dimensioning of the components of for example 70×70 mm,a CCD camera having 4000×4000 pixels would be necessary.

The read-out time of the corresponding information, at approximately 1s, lasts far too long and is far too great for rapid processing.

It is necessary to provide objective lenses which while having a fieldof view of 70×70 mm exhibit a freedom from distortion of 5 micrometers.Such objectives can be produced only at high cost and are heavy andlarge.

On account of the weight and size of the illuminating device and of theobjective lens, the known arrangements for determining the position andchecking the separation can scarcely be integrated into the equippinghead of an automatic equipping system; in this case, such an integrationis definitely to be ruled out with respect to a certain size of thecomponents. The solution which is optimal with regard to the equippingtime, involving a determination of position and checking during theshortest equipping path between component removal and componentpositioning, cannot then be implemented.

German Patent Application 35 46 216 discloses an arrangement fordetermining the position of components, in which arrangement theequipping head brings up an image sensor, such as for example atelevision camera, and the image sensor then records an image of thecomponent at the suction pipette of the equipping head. According to avariant, it is also to be possible to fit the image sensor on theequipping head. Having regard to the overall volume and the weight ofthe image sensor, this variant could however at best be feasible for theequipping of small components.

German Patent Application 33 40 084 discloses a device for the equippingof printed circuit boards or ceramic substrates with components, inwhich device the equipping head brings up a position pickup device, inwhich a relative displacement of the component in relation to atheoretical position related to the positioning axis of the equippinghead is ascertained. The position pickup device includes a frame, whichis provided along one frame side with a series of mutually adjacent,radiation-emitting elements and along the opposite frame side with aseries of mutually adjacent elements receiving the mentioned radiation.If now a component held at the suction pipette of the equipping head istransported into the frame, then the centrally disposed receivingelements lie in the shadow of the component. The ratio of the left-handand the right-hand receiving elements, which receive a beam, forms ameasure of the eccentricity of the component in the correspondingdirection.

SUMMARY OF THE INVENTION

The invention is based on the problem of reducing the constructionaleffort required for determining the position and/or checking theseparation and/or checking the coplanarity of the leads of componentsand of permitting a rapid processing.

The solutions to this problem are based on the common concept ofgenerating on the photosensitive surface of a local resolutionoptoelectronic transducer a direct shadow of the region of the leads atone side of a component. As a result of this direct shadow, it ispossible to entirely dispense with an optical imaging system.

In the case of the first solution, parallel light is used for thegeneration of the direct shadow. The position of the shadow edges of theleads on the local resolution optoelectronic transducer then permits arapid determination of position and checking of separation. The processcan be used for the checking of the separation of the leads in qualitycontrol or for determining the position and checking the separation inthe automatic planting of components.

According to the second solution which is especially suitable for SMDplanting, parallel light is again used for the generation of the directshadow, but in this case the local resolution optoelectronic sensor issecured to the equipping head. The light source generating the parallellight can then be brought up by the equipping head or alternatively canlikewise be secured to the equipping head.

According to the third solution, in each case one direct shadow of theregion of the leads at one side of a component is generated successivelyby illumination from two different directions on the photosensitivesurface of the local resolution optoelectronic transducer. Besides thedetermination of position and checking of separation, this additionallyalso permits a checking of the coplanarity of the leads. The process canbe used for checking the separation and checking the coplanarity inquality control or for determining the position, checking the separationand checking the coplanarity in the automatic equipping of components.

According to the solution fourth which is especially suitable for SMDplanting, in each case one direct shadow of the region of the leads atone side of a component is generated successively again by illuminationfrom two different directions on the photosensitive surface of the localresolution optoelectronic transducer; in this case, however, the localresolution optoelectronic transducer is secured to the equipping head.The illumination from two different directions can be undertaken by adevice which is to be brought up by the equipping head or by a devicefitted to the equipping head.

According to the sixth solution, a equipping head for the automaticequipping of printed circuit boards or ceramic substrates withcomponents is equipped with a suction pipette, a local resolutionoptoelectronic transducer and at least one light source; in this case,using the light source, in each case one direct shadow of the region ofthe leads at one side of a component is generated successively on thephotosensitive surface of the local resolution optoelectronic transducerfrom two different directions. As a result of the describedconstructional measures, a determination of position, checking of theseparation and coplanarity of the leads of the components picked up bythe suction pipette are made possible, in which case these proceduresare carried out in the path from the component preparation device to theequipping position in the equipping head and thus do not require anyadditional time. Further advantageous refinements of the processesaccording to the invention and advantageous refinements of the equippinghead according to the invention are set out below.

The local resolution optoelectronic transducer can be formed just by onesingle photodiode, provided that the latter is displaceable in twomutually perpendicular directions.

The further development of the process concerns a particularly preferredformation of the local resolution optoelectronic transducer by a line ofphotodiodes which is displaceable perpendicular to the line direction.Since lines of photodiodes are commercially available, even in thelength required for particularly large components, this solution isfeasible with a particularly low expenditure. It is in this caseexpedient to use a line of photodiodes, the individual photodiodes ofwhich have rectangular photosensitive surfaces which are arranged sothat the long edge of the rectangle is perpendicular to the linedirection. Such lines of photodiodes are particularly insensitive todust.

A photodiode matrix can also be used as a local resolutionoptoelectronic transducer, i.e. in this case it is possible to dispensewith movement of individual photodiodes or of a line of photodiodes.

Another refinement permits a determination of position, checking ofseparation and checking of coplanarity of the leads of components bycentral projection from two different directions. In this case, aparticularly low expenditure is required if two point light sourcesdisposed at a spacing from one another are used for the centralprojection from two different directions.

An additional refinement concerns the use of a laser diode as pointlight source. Such laser diodes are economical and moreover aredistinguished by low weight and by a good point characteristic.

If the point light source is fitted to the equipping head, thendetermination of position, checking of separation and checking ofcoplanarity of the leads of the components can be carried out withoutdelay on the shortest equipping path between component removal andcomponent positioning. It is then particularly favorable if the pointlight source is displaced synchronously with the line of photodiodesperpendicular to its line direction. As a result of this measure, aprecise shadow of the entire region of the leads at one side of acomponent is guaranteed with a small expenditure.

Yet another refinement permits, by a simple rotation of the respectivecomponent in steps of 90° and 180°, an encompassing of all lead regions.This rotation can then be undertaken, without additional expenditurewith the aid of the suction pipette of a equipping head.

More refinements concern the fitting of a line of photodiodes which isdisplaceable perpendicular to its line direction to the equipping head.As has already been mentioned, lines of photodiodes are commerciallyavailable even in the length required for particularly large components,so that the realization of the local resolution optoelectronictransducer in this case requires a particularly low expenditure. Inthese circumstances, in this case also again, a design which isparticularly resistant to dust is obtained if the individual photodiodesof the line of photodiodes exhibit a rectangular photosensitive surfacewhich is elongate perpendicular to the line direction.

It is particularly favorable to fit to the equipping head a point lightsource, preferably two point light sources which are disposed at aspacing from one another. In this case, here also again two laser diodesdisposed at a spacing from one another are to be preferred having regardto the low expenditure on cost, the low weight and the good pointcharacteristic to other point light sources.

A further refinement permits a particularly simple synchronousdisplacement of the point light sources and of the line of photodiodes.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the invention are shown in the drawings and are describedin greater detail hereinbelow.

In the drawings:

FIG. 1 shows the basic principle for determining the position andchecking the separation of the leads of components, in the case of whichbasic principle a direct shadow of the region of the leads at one sideof a component is generated by illumination with parallel light on thephotosensitive surface of a local resolution optoelectronic transducer,

FIG. 2 shows the basic principle of a first embodiment for determiningposition, checking separation and checking coplanarity of the leads ofcomponents, in the case of which basic principle in each case one directshadow of the region of the leads at one side of a component isgenerated successively by illumination with parallel light from twodifferent directions on the photosensitive surface of a local resolutionoptoelectronic transducer,

FIG. 3 shows the basic principle of an embodiment for determiningposition, checking separation and checking coplanarity of the leads ofcomponents, in the case of which embodiment in each case one shadow ofthe region of the leads at one side of a component is generatedsuccessively by central projection from two different directions on thephotosensitive surface of a local resolution optoelectronic transducer,

FIG. 4 shows a variant of the embodiment shown in FIG. 3, in the case ofwhich a line of photodiodes which is displaceable perpendicular to theline direction is used as local resolution optoelectronic transducer,

FIG. 5 and FIG. 6 show the arrangement of the line of photodiodes andpoint light sources corresponding to the variant shown in FIG. 4 in thechecking procedure and in the planting procedure, and

FIGS. 7 and 8 show the ascertainment of the spatial position of theleads of a component according to the variant shown in FIG. 4.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1 shows, in greatly simplified diagrammatic representation, anequipping head BK1, the suction pipette SP of which carries a componentB. The shown component B comprises a quad flat pack, which possesses tenleads A on each side of the component. A local resolution optoelectronictransducer W1 is secured to the equipping head BK1 in such a manner thatby illumination with a parallel light PL1 a direct shadow of the regionof the leads at one side of the component is generated on itsphotosensitive surface. From the position of the shadow edges of theleads A on the local resolution optoelectronic transducer W1 it is thenpossible to ascertain the position of the leads A, for example, inrelation to the axis of symmetry of the suction pipette SP and also tocheck the separation of the leads A. By rotation of the component Brelative to the local resolution optoelectronic transducer W1 in stepsof 90°, the regions of the leads of the remaining three sides of thecomponent can be encompassed for position determination and separationchecking. This rotation, indicated by a double arrow D, of the componentB is undertaken by a corresponding rotation of the suction pipette SP.

The photosensitive surface of the local resolution optoelectronictransducer W1 shown in FIG. 1 extends in the direction of the doublearrow Pf1 parallel to the pertinent component edge over the region ofthe leads A and perpendicularly thereto in the direction of the doublearrow Pf2. The extent of the photosensitive surface in the direction ofthe double arrow Pf2 is necessary having regard to any possiblerotations of the component B, since such rotations prevent a preciseparallel alignment of the component edge and transducer W1.

The photosensitive surface of the local resolution optoelectronictransducer W1 can be generated by a single photodiode FD, which iscorrespondingly displaced in the direction of the double arrows Pf1 andPf2. The photosensitive surface of the local resolution optoelectronictransducer W1 can however also be generated by a line of photodiodeswhich extends in the direction of the double arrow Pf1 and which isdisplaced in the direction of the double arrow Pf2. Furthermore, thephotosensitive surface of the local resolution optoelectronic transducerW1 can be formed by a photodiode matrix, the lines and columns of whichextend in the direction of the double arrows Pf1 and Pf2.

The parallel light PL1 for the generation of a direct shadow of theregion of the leads at one side of a component on the photosensitivesurface of the local resolution optoelectronic transducer W1 isindicated in FIG. 1 by a plurality of arrows, which are aligned inmatrix fashion corresponding to the directions Pf1 and Pf2. Thegeneration of the parallel light PL1 can in this case also be realizedby movement of a single light source in the direction of the doublearrows Pf1 and Pf2 or by movement of a linear arrangement, extending inthe direction of the double arrow Pf1, of light sources in the directionof the double arrow Pf2. The device which generates the parallel lightPL1 can be either brought up by the equipping head BK1 or directlysecured to the equipping head BK1.

FIG. 2 shows, in greatly simplified diagrammatic representation, anequipping head BK2, the suction pipette SP of which carries a componentB. A local resolution optoelectronic transducer W2 is secured to theequipping head BK2 in such a manner that by illumination with parallellight PL2 and PL3 from two different directions in each case one directshadow of the region of the leads at one side of the component isgenerated on its photosensitive surface successively. From the differingposition of corresponding shadow edges of the leads A on thephotosensitive surface of the local resolution optoelectronic transducerW2, it is then possible to compute the spatial position of the leads A.The computation of the spatial position of the leads A comprises adetermination of position as well as a checking of separation andcoplanarity.

By rotation D of the component B relative to the local resolutionoptoelectronic transducer W2 in steps of 90°, the regions of the leadsat the remaining three sides of the component can be encompassed fordetermination of position as well as checking separation andcoplanarity. This rotation D of the component B is in this case alsoagain undertaken with the aid of the suction pipette SP.

With respect to the construction and the mode of operation of the localresolution optoelectronic transducer W2, reference is made to thestatements concerning the local resolution optoelectronic transducer W1of the equipping head BK1 shown in FIG. 1.

The parallel light PL2 and PL3 is indicated in FIG. 2 by two groups ofarrows of differing direction. The generation of the parallel light PL2and PL3 can for example be undertaken by a linear arrangement ofcorresponding light sources, which are possibly moved in the directionof the double arrow Pf2. The corresponding light sources can either bebrought up by the equipping head BK2 or be directly secured to theequipping head BK2.

FIG. 3 shows, in greatly simplified diagrammatic representation, anequipping head BK3, the suction pipette SP of which carries a componentB. A local resolution optoelectronic transducer W3 is secured to theequipping head BK3 in such a manner that by central projection from twodifferent directions in each case one direct shadow of the region of theleads at one side of the component is generated successively on itsphotosensitive surface. From the differing position of correspondingshadow edges of the leads A on the photosensitive surface of the localresolution optoelectronic transducer W3 it is then possible to computethe spatial position of the leads A by using the laws of geometricaloptics. This computation is explained later in detail with reference toFIGS. 7 and 8. The computation of the spatial position of the leads Athen comprises, in this case also again, a determination of position aswell as a checking of separation and coplanarity.

By rotation D of the component B relative to the local resolutionoptoelectronic transducer W3 in steps of 90°, the regions of the leadsat the remaining three sides of the component can be encompassed fordetermination of position as well as checking of separation andcoplanarity. This rotation D of the component B is, in this case alsoagain, undertaken with the aid of the suction pipette SP.

With respect to the construction and the mode of operation of the localresolution optoelectronic transducer W3, reference is made to thecorresponding statements concerning the local resolution optoelectronictransducer W1 of the planting head BK1 shown in FIG. 1.

The abovementioned central projection from two different directions iseffected by two laser diodes LD1 and LD2 disposed at a spacing from oneanother. These laser diodes LD1 and LD2 which are fitted to the plantinghead BK3 are--as is indicated by arrows S--to generate successively ineach case one direct shadow of the region of the leads at one side ofthe component on the photosensitive surface of the local resolutionoptoelectronic transducer W3. Since the laser diodes LD1 and LD2comprise point light sources, there is here in each instance a shadowdue to central projection.

FIG. 4 shows a variant of the equipping head shown in FIG. 3. Theequipping head, designated here by BK4, carries at mutually oppositesides in each case one local resolution optoelectronic transducer W4.The two local resolution optoelectronic transducers W4 are in eachinstance formed by a line of photodiodes which is displaceableperpendicular to its line direction, i.e. in the direction of the doublearrows Pf2. In each instance, two laser diodes LD1 and LD2 which aredisposed at a spacing from one another are associated with the two linesof photodiodes.

In the embodiment shown in FIG. 4, by a once-only rotation D of thecomponent B relative to the two local resolution optoelectronictransducers W4 through 90°, the remaining two component sides can alsobe encompassed for determining the position as well as checking theseparation and coplanarity of the leads.

FIGS. 5 and 6 show, in greatly simplified diagrammatic representationfor the equipping head BK4 shown in FIG. 4, the arrangement of lines ofphotodiodes and light sources in the checking procedure and in theequipping procedure. It can be seen that the local resolutionoptoelectronic transducers W4 and the two associated laser diodes LD1and LD2, lying one behind the other perpendicular to the plane of thedrawing, are secured in each instance to a common mounting H. Themutually opposite mountings H are displaceable by means of shiftingdevices VE in the direction of the double arrows Pf2, i.e. in the courseof the checking procedure the local resolution optoelectronictransducers W4 are displaced synchronously with the associated laserdiodes LD1 and LD2 relative to the leads A to be encompassed. Theshifting devices VE are fitted to a longitudinal guide LF, in which thesuction pipette SP is mounted to be raisable and lowerable in thedirection of the double arrow Pf3 and rotatable in the direction of thedouble arrow D.

After the position determination and checking procedure shown in FIG. 5,the two mountings H are displaced radially outwardly according to FIG.6, so that the component B can be deposited without obstruction at thepredetermined equipping position of a printed circuit board LP bylowering the suction pipette SP. In the course of this positioning ofthe component B on the printed circuit board LP, the result of thepreviously performed determination of position is taken into account, asappropriate, by a corresponding correction. This correction can includeboth a displacement and a rotation of the component B relative to theprinted circuit board LP.

FIGS. 7 and 8 show, for the equipping head BK4 described hereinabovewith reference to FIGS. 4, 5 and 6, the ascertainment of the spatialposition of the leads A of a component B. FIG. 7 shows the localresolution optoelectronic transducer W4 which is formed by a line ofphotodiodes, the component B, disposed immediately therebelow, with theleads A and, below the same, the two laser diodes LD1 and LD2 disposedat a spacing from one another. The length, designated in FIG. 8 by L, ofthe line of photodiodes is in this case coordinated with the length ofthe component B.

In the vertical direction, the spacing between the lower side of theline of photodiodes and the two laser diodes LD1 and LD2 is designatedby A. In the horizontal direction, the spacing between the laser diodesLD1 and LD2 and the margin R, on the left in FIG. 7, of the line ofphotodiodes is designated D1 and D2 respectively. The shadow edges,generated successively by the radiation S of the laser diodes LD1 andLD2 on the line of photodiodes, of a specified lead A exhibit a spacingd1 and a spacing d2 respectively from the left-hand margin R of the lineof photodiodes in the horizontal direction. The horizontal spacing ofthis specified lead A from the left-hand margin R is shown by thecoordinate x, while in the vertical direction the spacing of the leads Afrom the lower side of the line of photodiodes is shown by thecoordinate z. As a result of the ascertainment of the coordinates x, adetermination of position and a checking of separation of the leads Acan be performed, while the coordinates z of the leads A permit a checkof coplanarity.

With the aid of the predetermined dimensions A, D1 and D2 and of thedimensions d1 and d2 recorded by the line of photodiodes, it is possibleto compute for the determination of position, checking of separation andcoplanarity the coordinates x and z with the aid of the relations##EQU1##

It can also be seen from FIG. 8 that the transducer W4 formed by a lineof photodiodes exhibits rectangular photodiodes FD and is displaceablein the direction of the double arrows Pf2. As a result of thisdisplaceability, an unambiguous shadow of the leads A is guaranteed,even in the event of a rotation of the component B. Moreover, thedisplacement of the line of photodiodes also permits the ascertainmentof the rotation of a component B, so that also any possible rotationscan be corrected in the course of the positioning on a printed circuitboard.

In the case of the preferred embodiment described hereinabove withreference to FIGS. 4 to 8, lines of photodiodes from the companyReticon, Sunnyvale, Calif., USA with the designation RL 4096 N are usedas the local resolution optoelectronic transducers W. These lines ofphotodiodes comprise in each instance 4096 individual photodiodesdisposed in a row; in this case, the photosensitive surfaces of theindividual photodiodes exhibit dimensions of 15×16 micrometers. Thelength of a line of photodiodes is 60 mm. Laser diodes from the companyHitachi Ltd, Tokyo, Japan with the designation HL 6711 C are used as thepoint light sources or laser diodes LD1 and LD2. These laser diodesexhibit a power of 5 mW and emit light having a wavelength of 670 nm. Asa result of the large number of individual photodiodes in the line ofphotodiodes, it is guaranteed that at high resolution only the necessaryinformation is recorded and can be read out in the shortest time of, forexample, 2 ms.

By way of departure from the described embodiments, in the case ofspecified equipping heads it can also be expedient to exchange thearrangement of lines of photodiodes and laser diodes. In this case, thelaser diodes are fitted to the equipping head above the component andthe lines of photodiodes are fitted to the equipping head below thecomponent.

Although other modifications and changes may be suggested by thoseskilled in the art, it is the intention of the inventors to embodywithin the patent warranted hereon all changes and modifications asreasonably and properly come within the scope of their contribution tothe art.

I claim:
 1. A process for determining position and/or checkingseparation and/or checking coplanarity of leads of components, which areremoved from a predetermined removal position of a component preparationdevice by means of an equipping and are positioned in a predeterminedposition on a printed circuit board or a ceramic substrate, comprisingthe steps of:successively illuminating one side of the component fromtwo different directions; generating in each case one direct shadow of aregion of the leads at the one side of the component on thephotosensitive surface of a local resolution optoelectronic transducerfitted to the equipping head, and computing a spatial position of theleads from differing position of corresponding shadow edges of the leadson the optoelectronic transducer.
 2. A process as claimed in claim 1,wherein said local resolution optoelectronic transducer comprises a lineof photodiodes which is displaceable perpendicular to a line direction.3. A process as claimed in claim 2, wherein said line of photodiodescomprises individual photodiodes which exhibit rectangularphotosensitive surfaces which are elongated perpendicular to a linedirection.
 4. A process as claimed in claim 1, wherein said localresolution optoelectronic transducer comprises a photodiode matrix.
 5. Aprocess as claimed in claim 1, wherein said illumination from twodirections uses at least one point light source.
 6. A process as claimedin claim 5, wherein said illumination from two directions uses two pointlight sources which are disposed at a spacing from one another.
 7. Aprocess as claimed in claim 5, wherein said point light source comprisesa laser diode.
 8. A process as claimed in claim 1, wherein saidillumination from two different directions uses at least one point lightsource fitted to the equipping head.
 9. A process as claimed in claims2, further comprising the step of:displacing the point light sourcesynchronously with a line of photodiodes perpendicular to its linedirection.
 10. A process as claimed in claim 1, further comprising thestep of:rotating the component relative to the local resolutionoptoelectronic transducer in steps of 90° or 180° to encompass all leadregions.
 11. A process as claimed in claim 10, wherein said step ofrotating comprises rotating the component by a suction pipette of theequipping head.
 12. An equipping head for the automatic equipping ofprinted circuit boards or ceramic substrates with components,comprising:a suction pipette to take up, transport and position thecomponents, a local resolution optoelectronic transducer and having atleast one light source, in which the light source generates successivelyin each case one direct shadow of a region of the leads at one componentside of a component taken up by the suction pipette by illumination fromtwo different directions on a photosensitive surface of the localresolution optoelectronic transducer and a spatial position of the leadsis computed from differing positions of corresponding shadow edges ofthe leads of the component on the optoelectronic transducer.
 13. Anequipping head as claimed in claim 12, wherein the local resolutionoptoelectronic transducer comprises a line of photodiodes which isdisplaceable perpendicular to its line direction.
 14. An equipping headas claimed in claim 13, wherein the individual photodiodes of the lineof photodiodes exhibit rectangular photosensitive surfaces which areelongated perpendicular to the line direction.
 15. An equipping head asclaimed in claim 12, further comprising: a point light source.
 16. Anequipping head as claimed in claim 15, further comprising: two pointlight sources which are disposed at a spacing from one another.
 17. Anequipping head as claimed in claim 16, further comprising: two laserdiodes disposed at a spacing from one another.
 18. An equipping head asclaimed in claim 13, wherein the point light sources are displaceable,by means of a common mounting, synchronously with the line ofphotodiodes perpendicular to its line direction.